The necessity of having to clean the hull of a boat periodically has long been known. Marine organisms must be removed for hull preservation and boat efficiency. Hulls may need old paint removed and new paint applied. Decks and other boat parts also need to be cleaned. If the boat is cleaned in the water, these cleaning tasks typically involve brushing both above and below the waterline. Sanding and the use of various cleaning agents and paint strippers may also be used above the waterline.
Although such cleaning may be effective to maintain a boat, boat cleaning is also known to result in air and/or water pollution, unless special precautions are taken. Brushing and sanding the hull release contaminants, such as old paint containing lead. If cleaners are used, they are usually toxic. Even if the deck of a boat is washed down with fresh water, polluting materials can be discharged or washed overboard.
Voluntary campaigns to control pollution from boat cleaning have been organized, but unfortunately these efforts have not been sufficiently effective. Because of continued concerns about the environment, ever more stringent federal and state laws and programs with tough penalties have been, or are being, enacted or proposed. Under these laws, severe fines and even jail terms have been imposed for those who still pollute the harbor waters as a result of boat cleaning.
A well-recognized way of avoiding water pollution is to clean the boat on land, although the problem of air pollution still exists. Moreover, having to haul a boat onto land to perform the cleaning tasks is inconvenient and expensive, especially burdensome for routine maintenance. As a result many boats are still being cleaned in the water notwithstanding the resulting pollution.
Apart from applicant, no practical and relatively economical solution to the environmental problems associated with routine boat cleaning is known to exist in the past. Some have tried to minimize the fouling of the boat's hull by covering it while moored. For example, the U.S. Patent to Faidi U.S. Pat. No. 5,549,069 discloses a bag that is pressed against the hull a shield the hull from the water. However, providing a protective cover for the hull does not directly address the problem of cleaning as described above, which in any event may be required. If chemicals are placed in the bag to dissolve marine growths, the chemicals may escape into the water. On the other hand, the U.S. Patents to Seiple U.S. Pat. No. 3,752,109 and to Feurt U.S. Pat. No. 4,784,078 do disclose floating hull cleaning equipment so that hull cleaning can take place in the water. These are complicated constructions, expensive to build and use, and do not allow routine boat maintenance at a typical dock or slip. Moreover, Seiple has no provision for avoiding pollution, and Feurt, although providing for the evacuation of contaminated water, does not prevent contaminates from escaping through the entrance and exit curtains.
To applicant's knowledge, applicant's prior U.S. Pat. No. 5,138,963 discloses the only method and apparatus that directly addresses the problem of cleaning a boat hull in the water and at a typical slip while avoiding pollution. Although the concepts disclosed in this earlier patent are still valid, the subject invention provides certain improvements.